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NTB: Fix/improve memory window index validation

PATCH In review Allen Hubbe 2 participants 4 messages Aug 31, 2015 – Sep 7, 2015

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NTB driver core NTB Intel driver
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Allen Hubbe

author
#0 lore raw

cover NTB: Fix/improve memory window index validation

Fix a range check on validating a memory window index, and make validation more strict for using memory window as a hardware errata workaround.

Allen Hubbe (2):
NTB: Improve index handling in B2B MW workaround
NTB: Fix range check on memory window index

 drivers/ntb/hw/intel/ntb_hw_intel.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)
Signature · 1 line
2.5.0.rc1
author
#1 lore raw

PATCH 1/2 NTB: Improve index handling in B2B MW workaround

Check that b2b_mw_idx is in range of the number of memory windows when initializing the device. The workaround is considered to be in effect only if the device b2b_idx is exactly UINT_MAX, instead of any index past the last memory window.

Only print B2B MW workaround information in debugfs if the workaround is in effect.

Signed-off-by Allen Hubbe <[email protected]>
---
 drivers/ntb/hw/intel/ntb_hw_intel.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)
drivers/ntb/hw/intel/ntb_hw_intel.c +16 -6
index c2bc56b67e63..fc6af2da8df0 100644
@@ -575,10 +575,13 @@ static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
 			 "Connection Topology -\t%s\n",
 			 ntb_topo_string(ndev->ntb.topo));
 
-	off += scnprintf(buf + off, buf_size - off,
-			 "B2B Offset -\t\t%#lx\n", ndev->b2b_off);
-	off += scnprintf(buf + off, buf_size - off,
-			 "B2B MW Idx -\t\t%d\n", ndev->b2b_idx);
+	if (ndev->b2b_idx != UINT_MAX) {
+		off += scnprintf(buf + off, buf_size - off,
+				 "B2B MW Idx -\t\t%u\n", ndev->b2b_idx);
+		off += scnprintf(buf + off, buf_size - off,
+				 "B2B Offset -\t\t%#lx\n", ndev->b2b_off);
+	}
+
 	off += scnprintf(buf + off, buf_size - off,
 			 "BAR4 Split -\t\t%s\n",
 			 ndev->bar4_split ? "yes" : "no");

@@ -1487,7 +1490,7 @@ static int xeon_setup_b2b_mw(struct intel_ntb_dev *ndev,
 	pdev = ndev_pdev(ndev);
 	mmio = ndev->self_mmio;
 
-	if (ndev->b2b_idx >= ndev->mw_count) {
+	if (ndev->b2b_idx == UINT_MAX) {
 		dev_dbg(ndev_dev(ndev), "not using b2b mw\n");
 		b2b_bar = 0;
 		ndev->b2b_off = 0;

@@ -1779,6 +1782,13 @@ static int xeon_init_ntb(struct intel_ntb_dev *ndev)
 			else
 				ndev->b2b_idx = b2b_mw_idx;
 
+			if (ndev->b2b_idx >= ndev->mw_count) {
+				dev_dbg(ndev_dev(ndev),
+					"b2b_mw_idx %d invalid for mw_count %u\n",
+					b2b_mw_idx, ndev->mw_count);
+				return -EINVAL;
+			}
+
 			dev_dbg(ndev_dev(ndev),
 				"setting up b2b mw idx %d means %d\n",
 				b2b_mw_idx, ndev->b2b_idx);

@@ -2008,7 +2018,7 @@ static inline void ndev_init_struct(struct intel_ntb_dev *ndev,
 	ndev->ntb.ops = &intel_ntb_ops;
 
 	ndev->b2b_off = 0;
-	ndev->b2b_idx = INT_MAX;
+	ndev->b2b_idx = UINT_MAX;
 
 	ndev->bar4_split = 0;
Signature · 1 line
2.5.0.rc1
author
#2 lore raw

PATCH 2/2 NTB: Fix range check on memory window index

In reply to Allen Hubbe

The range check must exclude the upper bound.

Signed-off-by Allen Hubbe <[email protected]>
---
 drivers/ntb/hw/intel/ntb_hw_intel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/ntb/hw/intel/ntb_hw_intel.c +1 -1
index fc6af2da8df0..865a3e3cc581 100644
@@ -240,7 +240,7 @@ static inline int ndev_ignore_unsafe(struct intel_ntb_dev *ndev,
 
 static int ndev_mw_to_bar(struct intel_ntb_dev *ndev, int idx)
 {
-	if (idx < 0 || idx > ndev->mw_count)
+	if (idx < 0 || idx >= ndev->mw_count)
 		return -EINVAL;
 	return ndev->reg->mw_bar[idx];
 }
Signature · 1 line
2.5.0.rc1
maintainer
#3 lore raw
In reply to Allen Hubbe
Quoted 6 lines · Allen Hubbe

Fix a range check on validating a memory window index, and make validation more strict for using memory window as a hardware errata workaround.

Allen Hubbe (2):
NTB: Improve index handling in B2B MW workaround
NTB: Fix range check on memory window index

Both of these look fine to me. Applying to my tree for 4.3.

Thanks,
Jon

Quoted 12 lines
 drivers/ntb/hw/intel/ntb_hw_intel.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

--
2.5.0.rc1

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